Method and apparatus for low power optical sensing and decoding of data

Abstract

A portable optical data reader for optically sensing and decoding data, comprising a carrier oscillator for producing a carrier signal at a predetermined frequency, an optical emitter electrically connected to the carrier oscillator for emitting optical radiation in an optical path to an optical data carrier at the predetermined frequency, an optical detector for detecting the emitted optical radiation returning from the optical data carrier thereby receiving the optical data and producing a detected electrical signal responsive thereto, and a double balanced demodulator electrically connected to the optical detector and the carrier oscillator for combining the detected radiation signal with the carrier signal to demodulate the optical data with the optical data carrier. A method of sensing and decoding optical data comprising-the steps of oscillating a carrier signal, transmitting the carrier signal to an optical emitter, thereby illuminating the optical emitter adjacent optical data, reflectively sensing the illumination from the optical emitter, thereby receiving the optical data, and demodulating the optical data by use of the oscillating carrier signal.